Condenser



J. H. SMITH Nov. 21, 1933.

CONDENSER Filed Oct. 10. 1931 4 Sheets-Sheet 1 J. H. SMITH Nov. 21, 1933.

CONDENSER Filed Oct. 10. 1931 4 Sheets-Sheet 2 Nov. 21, 1933. J s H 1,935,822

CONDENSER Filed Oct. 10. 1931 4 Sheets-Sheet 3 U OOO'OOO oooooooooooooooooo oooooo 000000 00 000000000000 oooooooooooo l 000000 OOOOOO OOOOOO 4 Sheets-Sheet 4 J. H. SMITH Nov. 21, 1933;

CONDENSER Filed Oct. 10, 1931 Patented Nov. 21, 1933 CONDENSER 'John H. Smith, 7 Application October 10,

Claims.

This invention relates tosurface condensers such as are ordinarily employed in condensing motive fluid (hereinafter termed steam) discharged from prime movers, such as turbines and engines, and the primary object of' the invention is to produce a high capacity condenser in which all the cooling or condensing surface is effectively utilized so as to obtain the highest possible rate of heat transfer under the conditions encountered.

The primary purpose of a commercial condenser is to reduce the back pressure on the prime mover and thereby contribute to a more effective utilization of the steam delivered to the prime mover. This is accomplished by condensing the steam exhausted from the prime mover. In the practical application of the condenser as a unit in modern power house equipment, the processes of condensation must be accomplished so as to produce the highest justifiable vacuum in such a way as to give the prime mover, discharging into the condenser, the benefit of that vacuum. That is to say, the effectiveness of a condenser is measured in terms of its ability to'condense-varying volumes of exhaust steam in a given interval of time and under such conditions as to produce the highest justifiable vacuum at the exhaust of the prime mover.

It will be apparent to those skilled in the art of condenser design that the ideal condenser should have a condensing surfaceof'infinite extent with all portionsthereof maintained at the minimum temperature of the cooling Water, and with such means for withdrawing condensate and non-condensible vapors and air as will not impede the flow of steam toward any portion of the condensing surface. With such ,a condenser the detrimental effect of resistance to steam flow in the vapor circuit would be practically eliminated, with the result that the prime mover exhausting into the condenser would, for all practical purposes, have the full benefit of such reduction pressure as is occasioned by the condensation processesat the temperature ofthe cooling water employed;

In the ideal condenser assumed, all portions of the condensing surface would be equally effective in absorbing heat from the steam and non-condensible vapors, and consequently the rate of heat transfer would be constant throughout the entire extent of the surface. Assuming thatbecause of the extent and location of the condensing surface the resistance to flow of steam and vapors toward the condensing surface is nil it will be apparent that all portions of the COnd S New York, N. Y.

1931. Serial No. 568,032

ing surface would be equally loaded, or in other words, each unit of surface area would assume an equal burden in absorbing heat from the exhaust steam and non-condensible vapors within the condenser.

Such an ideal is, however, not possible where space limitations are involved. Space limitations not only make it necessary to distribute the condensing surface throughout the volumetric space enclosed by the condenser shell or casing, but also necessitate such a distribution of this surface that the major portion of the surface is cooled by condensing liquid to which heat has previous ly been delivered in the processes of condensation, with the result that the effectiveness of the cooling surface varies, depending upon its position in the cooling water circuit of the condenser. If we assume, for example, the ordinary modern surface condenser of high capacity and of the single pass type it will be apparent that the cold-' est and'most effective condensing surface is the tube sheet at the inlet water box end of the condenser, and that the coldest and most effective portion of that tube sheet is immediately adjacent to the water inlet, or at the bottom of the condenser. It will also be apparent that the condensing water traversing the condenser tubes increases in temperature as it approaches the outlet water box, and that consequently there is a wide variation in the effectiveness of the condensing surface from the cold end (inlet water box end) to the hot end (outlet water box end) of the condenser.

It has been generally recognized that in order to increase the efficiency of the condenser the most effective portions of the condensing surface must be fully utilized in absorbing heat from the steam, vapors and air within the condenser. For this reason, designers of the modern condenser have attempted, by mechanical expedients, to increase the steam load at the cold end of the condenser, but in doing so, have overlooked physical laws relating to the flow of gases and have thereby impaired the efficiency of the condenser and imposed such resistance to flow within the vapor circuit that the prime mover exhausting into the condenser does not derive the full benefit of the vacuum produced by the condensation processes. That is to say, the pressure drop is so great that although a relatively high vacuum is obtained at some point within the tube bundle of the condenser, the prime-mover exhausting into the condenser does not derive the full benefit of that vacuum;

The practice of imposing resistance to steam temperature and lowest absolute pressure flow within the vapor circuit of the condenser in itself occasions additional resistance to flow by creating turbulence and eddies, not only within the confines of the condenser, but also within the passage between the exhaust of the prime mover and the condenser, with the result that the pressure drop is not only unnecessarily large but considerable resistance to flow is encountered in the exhaust passage of the prime mover.

In the'condenser embodying my invention I have attempted, so far as space limitations and practical conditions permit, to eliminate resistance to flow in the vapor circuit of the con-'- denser, with the idea 'of promoting a substantially unrestricted, tranquil flow toward the more effective cooling surface of the condenser. This, as hereinafter more fully pointed out, contemplates a tube distribution and an arrangement of tube spacers or supports such that 'thevelocity energy of the exhaust steam is dissipated within the tube bundle, and the steam and vapor move along substantially natural lines of flow from all portions of the condenser toward the zone of highest heat head.

An object of my invention is therefore, to provide a surface condenser of large capacity in which the distribution of the condensing surface and other features are such as to provide adequate flow areas for the gaseous media throughout all parts of the tube bundle so as to permit a natural and tranquil flow within the vapor circuit toward the more effective portions of the condensing surface. 7

A further object is to produce a high capacity condenser so constructed and arranged that the 'air and non-condensible vapors are withdrawn at such a point as to promote a natural flow of the gaseousmedia toward the zone of lowest within the condenser shell. f

A further object is to produce a high. capacity condenser in which the condensing surface is so distributed and arranged as to not only dissipate the velocity of the exhaust steam entering the ,condenser inlet but also to reduce the distance through which the maximum amount of condensate falls, and to provide increased areas through which. condensate mayfall and thereby reduce the resistance to vapor flow below that ordinarily encountered in the modern condenser.

A still further object is to produce a surface condenser of high capacity in which new and improved means are employed for supporting the tubes, and in which the detail arrangement and structural features are such as to produce a condenser having improved characteristics both from the standpoint of structure and operation.

These and other objects which will be made apparent throughout the further description of the invention are'accomplished by means of a condenser embodying the features herein described and illustrated.

Figure 1 is a diagram illustrating the lines of natural flow within the vapor circuit of a theoretical condenser and illustrates a principle of my invention;

Fig. 2 is adiagrammatic, transverse sectional view of the theoretical condenser shown in Fig. 1, and illustrates the. theoretical sub-division of the condensing chamber into a number of duplicate condensers located side by side and each similar to the other; 7

Fig. 3 diagrammatically: illustrates a condenser which has heretofore been assumed to be of the ideal shape;

The diagrams of Figs. 4 and 5 illustrate respectively transverse and longitudinal sectional views of a form of condenser predicated on the theory of constant velocity of the fluid medium and equal condensation per tube; I

Figs. 6 and 7 diagrammatically illustrate transverse and longitudinal sections of a condenser embodying the principle of my invention;

Fig- 8 is a diagrammatic view illustrating a tube arrangement such as may be employed in connection with my invention;

Fig. 9 is a diagrammatic longitudinal sectional 'view along the line IX-IX of Fig. 10, and illustrates a condenser embodying my invention with all but the lowermost row of tubes omitted for convenience of illustration;

Fig. 10 is a partial transverse sectional view along the line XX of Fig. 9;

Fig. 11 is a fragmental transverse sectional elevation of a condenser and illustrates a form of movable tube support which may be employed in connection with my invention;

Fig. 12 is a fragmentalplan View of the movable supports illustrated in Fig. 11 and shown in connection with the fixed support therefor; Fig. 13 is a fragmentallongitudinal sectional view (along the line XIIIXIII of Fig. 14) of a condenser and illustrates one feature of my invention; and

Fig. 14 is a fragmental transverse sectional view of the condenser illustrated in Fig. 13.

In producing the condenser embodying my invention I employ a tube spacing such as to closely approximate what I term a natural flow condition throughout the vapor circuit of the condenser. The meaning of the'term natural flow as here employed may be ascertained from the following: If'the ideal condenser heretofore discussed, is considered from the standpoint of practical space limitations, it will be apparent that the tube sheet 8 adjacent the water box 9 in the diagrammatic condenser illustrated in Fig. 1 approximates the ideal condensing surface. If it is assumed that the interior of the condenser shall i. e., the chamber 10-is filled with exhaust steam, that no air or non-condensible vapors are present, and thatthe condenserv inlet communicates with a supply of such steam capable of being delivered to the condenser without turbulence and under conditionswhich promote a tranquil stream line flow into,'and through the condensing chamber, and if it is further assumed that mechanical resistance to flow, suchas tubes, are omitted it will be apparent that the more or less quiescent atmosphere of steam within the condensing chamber 10 will be disturbed as soon as the tube sheet 8 is subjected to a flow of cooling liquid, because condensation will immediately start on, and. in the immediate neighborhood of, the tube sheet, and a flow of steam toward the tube sheet will immediately take place. It will, however, be apparent that the heat absorption by the tube sheet will occasion at least a theoretical temperature difference across that sheet because the lower ,edge of the sheet is cooled by a flow of water to which heat has not been previously delivered by the processes of condensation, whereas other portions are cooled by water which has absorbed heat from the steam as it is condensed.

It therefore follows that the lower portion of the tube sheet immediately adjacent its lower end, will constitute the most effective condensing $llrface, and that condensation will be most effectively carried on at, and adjacent to this portion of the tube sheet- This will tend to produce a pressure difierence within the condensing chamber with the lowest pressure immediately ad- 5 jacent the most effective condensing surface i. e., the lower edge of the tube sheet-with the result that the steam within the condenser will move toward the tube sheet and generally toward the most effective portion of the tube sheet, or the region of lowest pressure. This condition,- while preventing the establishment of a quiescent atmosphere within the chamber, will occasion a tranquil and natural flow of-steam from all parts of the chamber and along lines substantially as indicated by the flow lines in Fig. 1. That is to say, the steam flow within the chamber 10 and within the exhaust passage leading to that chamber, will be influenced by the location of the region of highest heat head and the resultant condensation, and consequently more steam will enter the portion of the inlet 11 adjacent the tube sheet than the more remote portions thereof, and the streams of steam en tering the inlet will be gradually turned sothat the flow throughout all portions of the chamber 10 will be toward the cold tube sheet, but in the general direction of the region of highest heat head within the chamber or toward the edge of the tube sheet 8 most remote from the inlet If new we consider that the steam within and entering the chamber 10 is contaminated by noncondensible vapors and air it will be apparent that by removing these non-condensible vapors. or gases from the shell at points adjacent to the lower edge of the tube sheet, the natural stream line fiow will be promoted rather than impeded, with the result that the gaseous media will move toward the'more efiectivecondensing surface, without abrupt changes in direction and consequently without turbulence.

I have illustrated the diagrammatic condenser of Fig. 1 as provided with anair ofr'take port 12, which is located immediately adjacent to the most efiective portion of the cooling surfacei. e., adjacent the lower edge of the tube sheet 3. A shield 12a is so arranged that the effective communication between the chamber 10 and the oiftake 12 extends transversely across the tube sheet 8 and immediately adjacent the lower edge thereof.

In the diagram I have also located the condensate well 13 in'the neighborhood of the tube sheet 14 located adjacent the outlet water box 15. It will, of course, be apparent that in the diagram (Fig. 1) I am assuming some ideal though impractical means which will not occasion resistance to steam flow within the condensing chamber, but which will'conduct cooling water from the water box 9 to the water box 15 and will maintain a continuous flow of water over both tube sheets, but in which the water traversing the tube sheet 14 is substantially warmer than that traversing the tube sheet 8.

By locating the hot well 13 at a point remote from the tube sheet 8 the condensate, in moving from the zone of condensation, is necessarily exposed to some steam which has not been subjected to the cooling effect of the colder tube sheet 8, with the result that the-condensate will take up heat from such steam and consequently be delivered to the condensate well at a temperature somewhat above the temperature at which it is condensed.

'It will-be apparent that the condenser may be considered as a plurality of duplicate narrow condensers located side by side, without separating walls, and so arranged that each receives steam in equal amounts from the common inlet and each, in eifect, having an air ofitake port located immediately adjacent the most effective condensing surface. In Fig. 2 I have diagrammatically illustrated this by means of dot dash lines and have necessarily shown the assumed duplicate condensers of appreciable width. The drawings, however, illustrate the fact thatlthe interior of the condensing chamber may be considered as made up of any number of duplicate condensers located side by side, transversely of the chamber, and each extending from the top to the bottom and the entire length of the chamber. By so considering the condenser it will be clearly apparent that the steam entering each such small condenser will follow natural flow lines toward the most effective condensing surface with minimum resistance to flow and consequently with minimum pressure drop, as will be more fully commented upon in connection with tube spacing.

As before stated, space limitations make it necessary to distribute the condensing surface in two planes and for this reason condensing tubes are employed in surface condensers. My invention contemplates tubes extending longitudinally of the condenser from the tube sheet 8 at the cold end, to the tube sheet 14 at the hot end of the condenser, but it also contemplates a special arrangement of these tubes and of their supports so as to promote, as far as possible, the conditions of natural flow within the condensing chamber. 1

In installing tubes the situation must be conside-red both from the standpoint of the thermal and the mechanical eifect of the tubes. As stated, the cooling water traversing the tubes is progressively heated as it moves from the tube sheet at the cold end of the condenser toward the tube sheet at the hot end of the condenser, and consequently the surface of each tube is progressively less effective as condensing surface as the hot end of the condenser is approached. Then too, the introduction of the tubesinto the condensing chamber interposes a mechanical barrier to the flow of steam into and through the chamber. This is further accentuated by the fact that space limitations ordinarily compel the use of long tubes, inorder to obtain adequate condensing surface and to effectively utilize the available cooling effect of the cooling water, and the long tubes necessitate the use of tube supports. Then too, the water of condensation dropping from the upper tubes 01' the nest or bundle mask or shield the lower tubes and reduce their effectiveness as condensing units, and this water also cuts down the available flow area and constitutes a barrier interposedin the vapor circuit, of the condenser.

Tube supports, as heretofore employed, not only prevent the natural flow of the gaseous media within the condensing chamber, butalso divide the chamber into sections. In fact, the modern tendency has been to employ tube supports for the purpose of sectionalizing the condenser, since the general attitude hasbeen that the performance of the condenser is improved by mechanically directing the flow of gaseous media by means of partitions, baiiles, directing ports, passages or throttling valves, toward the most eifective surface or by imposing such resistance to flow within the vapor circuit as will accomplish this result.

I, however, recognize the tubes and the tube supports as necessary evils, and my attempt is to minimize the detrimental effect occasioned by their use and to minimize as far as possible resistance to natural flow. I, therefore, so position the tubes within the condenser'so as to maintain, as far as possible, the natural flow condition heretofore described, and 'I so form the tube supports that they will impose a'minimum resistance to the natural flow in the vapor circuit.

It is recognized that the tubes first exposed to the exhaust steam entering the condensing chamber are the most efiective tubes, from the standpoint of condensation, because the steam has easy access to them without the blanketing effect of the condensateand the air or other non-condensible gases encountered in connection with lower tubes of the nest, consequently it may be assumed that the capacity for condensing steam is greatest in these tubes as compared to'lower tubes of the nest. the tubes adjacent the inlet of the condensing chamber are detrimental because they occasion mechanical resistance to the flow of steam entering the tube bundle, and that while these tubes are effective ascondensing units they necessarily render other tubes of the bundle less effective by -impeding the entrance of the steam through the bundle or through the condensing chamber and by increasing the shower of condensate on these tubes. Consequently in distributing the condensing surface throughout the alotted or available volumetric capacity of the condensing chamber it isnecessary to obtain a balance between thepositional advantage and the positional disadvantage of the tubes first subjected to themcoming steam. I obtain this balance by positioning all the tubes within the condenser so as to obtain a close approximation of the natural flow condition illustrated in Fig. 1, and in so doing I contribute to a maximum dissipation of the velocity of the exhaust steam entering the condenser shell so as toavoid a building up of steam pressure by an abrupt checking of the steam velocity or by an abrupt turning of the lines of steam flow.

In connection with tube spacing it might be stated that Fig. 3 illustrates what is commonly, but I believe erroneously, considered to be a condenser of idealshape and of ideal tube spacing. The assumption is that the cross sectional area of both the condensing chamber and of the spacing between the tubes should be reduced to correspond to, or compensate for the reduction in steam volume occasioned by the progressive condensation of the steam as it penetrates the bundle of tubes. It is further assumed that each tube condenses the same amount of steam and that the steam or vapors flow at a constant velocity through the tube bundle by reason of the restrictionin flow areas.

It should be said in connection with Fig. 3 that the ideal condensing surface, heretofore discussed, would approach the shape of the tube sheet of Fig. 3, except that the sheet should be of infinite width adjacent the inlet to the condensing chamber. It should also be said that the practical necessity of distributing condensing surface in three dimensions, i. e., throughout a volumetric space, as distinguished from the ideal of maintaining all the surface within a single plane, introduces conditions which make the condenser of Fig. 3 a false standard, from the standpoint of practical operating conditions.

It is, however, apparent that The necessity of distributing condensing surface through three dimensions, immediately introduces tube length into the problem and, as we have said, tube length necessarily results in the practical difficulty of temperature variation. That is to say, under practical operating conditions it is impossible to maintain all portions of the condensing surface equally cold and therefore equally effective. The tube sheet at the cold end of the condenser necessarily discloses some effect of heat absorption by the cooling water passing over it, but this effect is more pronounced, and in fact is quite marked, in connection with the tubes of a condenser. This, therefore, means variation in heat head throughout different portions of the condensing chamber. A

It is axiomatic that heat head induces steam flow to the zone of lowest temperature, and that pressure drop, resulting therefrom, limits the flow up to the point of equilibrium. The natural tendency is for steam to seek the zone of highest heat head, i. e.,"to flow toward the cold end of the condensing chamber. The steam will follow this natural'direction of flow unless it is mechanically hampered. 'As stated, the tubes themselves impose resistance within the vapor circuit, but even so, the flow toward the region of highest heat head will be in such quantities as will establish a balance between the urge, occasioned by the heat head, and the resistance to vapor flow encountered. That is to say, a condition of equilibrium will be established in the vapor circuit of every condenser, which will depend upon existing heat head and the resistance to flow encountered, so that every condenser may be said to be operating at its characteristic pressure dropi. e. the pressure difference between the point of steam entry into the bundle and the point of lowest absolute pressure within the condensing chamberwhen a balance has been established between the flow tendency, occasioned by heat head, and the resistance to that flow.

The point of lowest absolute pressure is manifestly at the exit from the tube bundle and adjacent the cold tube sheet. It will be apparent that in theoryexcluding the high velocity and directional effect in the turbine exhaustthe maximum amount of steam, per increment of tube length, enters the bundle at a maximum velocity at the cold end, whereas a minimum amount enters at a minimum velocity at the hot end of the condenser, with the result that a maximum amount of latent heat is extracted and a maximum amount of condensation, per square foot or unit of condensing surface, is accomplished at the entering edge of the tube bundle adjacent the cold end; The natural consequence of this condition is that there is a minimum amount of condensation persquare foot of condensing surface at the exit edge of the bundle at the cold end. This conditionis necessarily reversed at the hot end of the condenser where there is a minimum of condensation, per unit of surface, at the entrance edge of the bundle and a maximum at the exit edge.

From the foregoing it is apparent that con trary to common belief, steam or water vapor penetrates the full depth of the tube bundle at both ends of the condenser, but in far greater quantities per square foot of tube surface, at the hot than on the cold end. This is occasioned by the fact that the maximum pressure drop is in the plane of the tube sheet at the cold end and the minimum pressure drop is in the plane of the tube sheet at the hot end of the condenser, since otherwise all steam would .be condensed on the cold tubesheet and an increment of length at the cold end of all the tubes, and each tube would condense an. equal amount of steam and the vacuum temperature would closely approach the discharge .water temperature. To obtain such results it would be necessary to employ a condenser shell of the cross sectional shape of Fig. 3, but having a steam inlet of infinitewidth. Under such conditions, a single tube only, would be necessary at the exit terminal. to condense the final unit of steam.

Equal distribution of steam per tube can only be realized under conditions of infinite entrance area and zero pressure drop. Consequently the ideal of Fig. 3 cannot be realized in practice,

since the reduction from infinite area to a prac-[ tical dimension introduces velocity, pressure drop, and the thermal necessity for a third dimension, i. e., a substantial tube length. It is therefore obvious that any attempt to follow the ideal shape of condenser or tube bundle as illustrated in, Fig. 3, with a View to the maintenance of constant steam velocity through the bundle and along any plane paralleling the tube sheet, is fundamentally'wrong and that in practice the desired condition of constant velocity is approximated only in the plane of the tube sheet at the hot end of the condenser and even here it cannot be considered a reality because of the presence of pressure drop.

It may therefore be stated thatthe condition of constant velocity cannot be approached. nor.

dition ideal (viz., natural flow condition), which can be closely approximated within the spacelimitations encountered in practice. Instead of restricting space as condensation proceeds, I, in efliect, maintain flow areas and thereby obtain a net increase in area per unit of steam traversing the bundle. I

A further reference to the so-called shape ideal, as diagrammatically illustrated in Figs. 4 and 5, will make it apparent that unless the ideal of constant velocity and equal condensation per tube increment in any vertical plane, is accomplished, there will necessarily be spreading of the steam from vertical plane to plane, and in the direction of the hot tube sheet,-by reason of the attempt to maintain the entering, velocities throughout. the entire depth of the tube bundle.

The shaded areas in Fig. 4 are representative of the assumed ideal of constant velocity and equal condensation per tube. The view also illustrates the reduction in flow areas made for the purpose of forcing a constant steam or vapor velocity. Constant velocity of the fluid media, however, cannot be maintained in practice because pressure drop varies as V L (V=velocity;

, L distance of travel), consequently the effect of theshape' ideal is to continually force steam toward the lessv effective condensing surface or toward the hot end of the condenser. If, however, constant flow areas are maintained between horizontally spaced tubes, steam quantities can be increased in any transverse plane for a given L and a given pressure drop, and thus a material reduction in the amount of entering steam forced toward the hot end of the condenser is effected.

Figs. 6 and '7 are diagrammatic viewsillustrative of the principle I employ-in connection with tube spacing. In Fig. 6 the tubes are arranged in parallel rows as distinguished from the converging rows of Fig. 4. In both Figs. 4 and 6 the shaded areas are representative of the constant velocity and equal condensation per tube, theory. Fig. 6, however, is a radical departure from the space ideal in that the shell of the condenser rectangular instead of triangular and for this reason accommodates a characteristically different tube arrangement, i. e., an arrangement in which the tubes are in vertical rows located in parallel relation. Fig. 6 discloses unshaded areas through which steam can'fiow in any direction and which, therefore, accommodates the natural flow condition heretofore described. Figs. 6 and 7 disclose the heretofore mentioned duplicate condensers located side by side.

It will also be apparent tothose skilled in the art that assuming an equal pressure drop for Figs. 4 and 6, the condenser of Fig. 6 will result in an increased quantity of steam moving toward the cold end at any plane C-C, when equilibrium is established. If, as illustrated in Fig. '7, we assume that air is withdrawn at a point adjacent to the exit of the tube bundle and immediately adjacent to the cold end of the condenser, it willbe apparent that the pressure drop along all flow lines A, B, C, D and E of Fig. 5 is equal. In the case of'a tube sheet layout as in Fig. 4, the. resistance to flow toward the cold end causes deeper penetration of steam through the tube bundle as the hot end is approached. This results from the natural condition of steam flow.

In Fig. 7 I have assumed a tube layout, such as illustrated in Fig. 6, and I have reproduced in full lines the flow linesA-E of Fig. 5. It will, however, be apparent that-because of the increased flow areas, represented by the unshaded portions of Fig. 6, the flow lines actually establishedin a condenser, such as illustrated by Figs. 6 and 'l, may be represented by the dotted lines A, B, C, D and E. It will also be apparent that flow lines, such as E of Fig. 5, tend to disappear as more steam is condensed at the cold end. The net result is that the time element, in effecting a given amount of condensation, is reduced and r the most efficient utilization of the condensing surface and the available volumetric capacity in which to install that surface, is accomplished.

I believe that constant velocity, as that term is at present applied to conditions in the socalled modern condenser, is neither possible of obtainment noris it desired. On the other hand, it is apparent that the natural tendency is for the greater quantities of steam to enter the bundle at the cold end of the condenser and it is necessary to provide flow areas and space to accommodate this condition. The condenser illustrated in Figs. 6 and 7 ofiers increasing, instead of decreasing flow areas as steam condenses out, consequently the number of vertical rows of tubes may be increased toward the exit side of the bundle or to be more specific, as the bottom of the condenser is approached. Moreover an increase in the number of vertical rows can be accomplished in such a way asto maintain a substantially constant ratio between the horizontal spacing of the rows and the uncondensed vapor traversing the condensing chamber. That is to say, the flow areas may be decreased in the hori- 1 adequate flow areas maybeprovided to accommodate the natural tendency of the steam to respondto the existing conditions of heat head. In this way it is possible to approximate the natural flow condition, which to some extent involves an approximation of constant velocity.

It will be apparent that while a tube arrangement, such as in Fig. 6, contributes to a close approximation of the ideal condition of natural flow, that some compromise in the distribution of condensing surface must be made in practice in order to include the condensing surface within the allotted space and in order to make the cost commensurate with th'e advantage gained by employing a condenser. For this reason I consider the condenseras divided into sections from the top to the bottom, with the idea of increasing the number of vertical rows of tubes as the bottom of the condenser is approached. By employing a condenser having a rectangular shell, or wide at the'bottom, I can so space the vertical rows as to provide sufiicient space or flow areaat the inlet to each section so as to at least closely approximate natural flow conditions.

In Fig. 8 I have diagrammatically illustrated a condenser and have disclosed a satisfactoryparrangement of tube spacing. It will be noted that the tube spacing in the condenser there illustrated, is such as to in effect divide the con-. denser into three sections which I have respectively designated T, M and B. After analyzing the steam velocities for any given condition I may arbitrarily adopt a satisfactory vertical spacing for the tubes and then adopt a hori- I zontal spacing for the tubes of the bottom section which will satisfy the conditions encountered in that section and provide adequate area for ac commodating the naturalflow condition. I then adopt a horizontal spacing for the section M,

i which satisfies the flow conditions for that section and which also provides flow areas at the inlet to the bottom section B, which will satisfy the conditions for penetration to thatsection. That is to say the horizontal spacing of section i M must be such as to satisfy the conditions within that section and also a condition within section B, which is based on the assumption that equal condensation per tube increment is obtained from the top to the bottom of the condenser.

I follow the same procedure in connection with the top section T and adopt a horizontal spacing which will provide adequate admission area to satisfy conditions within section T and also provide adequate space for the delivery of steam to sections M and B.

On the assumption thateach tube condenses the same amount of steam I so apportion the flow area in the horizontal plane at the entering .edge of each section that the flow area at any such plane is in the sameproportion to the total entering area, at the top of the condenser, as the number of tubes below such plane is'to the total number of tubes.

In the preliminary analysis of the flow conditions within the condensing chamber I find it desirable or at least convenient to divide the width of the'chamber into a number of sections of equal width and to treat each of these subdivisions as a separate condenser having a steam inlet located at the top of the condenser and an air and non-condensible. vapor offtake located at the bottom of the condenser and immediately adjacent to the tube sheet at the cold end of the condenser; That is to say, I determine the tube layout for one such sub-division and then dupli-t catethe layout in the other sub-divisions. The completed condenser includes duplicate groups of tubes located side by side, each group extending from the top tothe bottom of the condenser.

For example, I may first, divide the width of the condenser into three approximately equal parts, L, C and R, as shown in Fig. 8. One such part is then divided into three horizontal sections B, M and T. The length of the horizontal sections may vary, since, as previously stated, I am attempting to strike a balance tween an ideal condition and a practical condition forced upon me byavailable space for the condenser and by cost considerations. It will be readily apparent that the free space necessary to accommodate the desired flow conditions may be readily estimated for the bottom section B of the sub-division C. and after this isdetermined it is a relatively simple matter to estimate the number of vertical rows of tubes permissible in'the space in question, since each vertical row obstructs the vertical steam space to the. extent of the diameter of the tube.

7 Under practical conditions the problem of determining the horizontal tube spacing for the lowermost. section B to some extent resolves itself into a mechanical one, since it is necessary to consider the tube supports or spacers both from the standpoint'of mechanical strength and from the standpoint of openings therein for the passage of steam to accommodate as close an approximation of the natural flow condition as it is possible to obtain within the available space. As heretofore stated, I may arbitrarily adopt a vertical spacing for the tubes which is again controlled bythe question of strength in the tube support.

Where tubes are employed, a vertical spac ing of an inch and A; may be satisfactorily employed. An approximation of natural flow conditions may be obtained by employing a horizontal spacing of about 1 center to center of tubes for the tubes of section B. 1 This provides suflicient space between. the vertical rows of tubes for fairly large openings in the tube support and at the same timeprovides the necessary mechanical strength in the. tube supports. It will, of course, be understood that where space conditions are limited a somewhat less horizontal spacing may be adopted without entirely sacrificing the advantages to be gained in the lowermost section by providing openings in the tube supports between the vertical rows of that section. 7

Having adopted a vertical and a horizontal spacing for the bottom section, the depth'of the bottom section becomes a function of the free space at theentering edge of that section. In other words, a preliminary estimate can be made of the number of tubes in the bottom section from the determined spacing, and thedepth is then determined by assuming a satisfactory vapor velocity at the entering edge of that section. If equalcondensation per tube in that section is assumed, it is apparent that the depth of the section more or less determines itself from the quantity of steam which will pass through the free space at the entering edge of the section at the assumed velocity. .That is to say, the depth of the section is a function of the free space at the entering edge of the section, or vice versa, the free space at the entering edge is a function of the depth.

Having adopted a spacing for the bottomsection B and having determined the permissible depth of that section the number of tubes-in the section can be determined. The next step necessarily resolves itself into a cut and try procedure since, as before stated, space limitations prevent the full realization of the advantages to be gained from a natural flow condition, and some compromise must be made between practical conditions and theory. Knowing the entire volume of steam to be condensed and assuming a permissible velocity at the entering edge of the entire tube bundleviz., preferably the same velocity assumed in connection with the entering edge of the bottom sectionI estimate the necessary free space at the entering edge of the entire tube bundle i. e., the entering edge of the top section. Knowing the diameter of the tubes it is then a simple matter of arithmetic to calculate the desirable spacing at the entering edge of that section. It is then necessary to determine the number of horizontal intermediate sections to be employed. The fewer horizontal sections, such as T, M and B, employed, the closer the approximation to the natural flow condition, but practical conditions may force the necessity of employing several such sections. Where conditions permit I prefer three sections as illustrated since this gives a relatively close approximation to-the desired flow conditions.

Knowing the total number of tubes necessary to condense the entire volume of steam entering the vertical sub-division and knowing the number of tubes desirable for the bottom section, the problem is to obtain the best distribution of the remaining tubes between the top and the one or more intermediate sections to be employed, always assuming a permissible velocity at the entering edge of each intermediate section--viz., preferably the velocity assumed in connection with the entering edge to the top and bottom sections and always realizing the desirability of fully loading at least the cold ends of the tubes of the bottom section.

The depth of each horizontal section is'controlled bythe free space at the entering edge ofthat section, and by the other conditions pointed out in connection with the design of section B, the only difference being that the free space at the entering edge of each such section must not only provide sufficient area for supplying steam to that section, but also to all sections below it.

The tube spacing may be preliminarily determined in this way for one vertical sub-division and after being checked with the idea of obtaining the proper apportioning of the tubes among thevarious horizontal sections (T, M and B etc.) so that adequate free space is provided for the delivery of steam to the bottom and other lower sections and so as to insure that the requisite number of tubes are included in the bundle, the tube spacing finally decided upon is duplicated in the other sub-divisions or vertical groups of tubes, as shown in Fig. 8. In this connection it will be apparent that the continuous vertical rows of tubes 26b, which in effect bound the central sub-division are not duplicated in the sub-divisions L and R, but that the side wall of the shell is so located with relation to the other vertical rows of tubes as to provide theproper steam space between it and the adjacent tubes to deliver the desired quantity of steam from the top to the bottomof the condenser.

. It will, of course, be apparent that the procedure in determining the number of horizontal sections and the horizontal tube spacing for each such section may be materially varied. The designer, knowing the total quantity of steam to be condensed per unit of time, can first determine by well established empirical rules the total number of tubes to be employed. He may then adopt a horizontal spacing for the tubes of the top section which will provide sufficient free space at the entering edge of the bundle to accommodate this flow at an assumed desirable velocity. By adopting an arbitrary vertical spacing and a desired depth for the uppermost horizontal section, he can then not only preliminarily estimate the number of tubes to be employed in the top section, but he can also preliminarily determine thequantity of steam remaining to be condensed by condensing surface located below the top section. It will then be necessary to apportion the tubes between the bottom section and such intermediate sections as conditions indicate and the remaining procedure may be carried forward as above described, but always with the idea of employing' a horizontal spacing which will provide suflicient area for the delivery of steam not only to the section under consideration but to all secmo tions below it. I

As stated previously, the preliminary layouts are necessarily cut and try or tentative layouts and when completed may show the necessity for a change in sections and a respacing of the tubes in some or even all of the sections, in order to pass the requisite quantities of steam remaining uncondensed to the lower sections of the condenser.

It may be stated that the tube layout is based on the known fact that the cold end of the condenser has the greatest potential possibilities for condensing steam, and the intent is to permit as much steam to move toward the more effective condensing surface as will flow in that direction in response to the natural urge occasioned by the location of the region of highest heat head. Then, too, it is a well established fact that the cold ends of the uppermost tubes of the bundle, that is, of the tubes with which the entering steam first comes into contact, condense the max- 110 imum amount of steam, whereas other tubes in the bundle having the same potential possibilities for condensation because of the temperature conditions, condense far less steam, because of their less favorable location. This fact makes it quite apparent that the most effective condensing surface is not bein effectively and efliciently utilized in the so called modern condenser, and it is an object of my invention to overcome this difficulty and to so reduce the resistance to natural flow within the vapor circuit that all portions of the more effective condensing surface will receive steam in quantities commensurate with their capacity to condense steam. It is well known that a minimum amount of steam is condensed at the hot end of the condenser, but at the same time, a far greater amount of steam penetrates the hot end than the cold end of the tube bundle. My intent is to provide a natural path of flow from all portions of the con- 1st denser toward the more effective condensing surface and in this way to provide an easy and natural path for the steam from the hot end of they condenser toward the region of highest, heat head.

By employing parallel rows of tubes, as dis' tinguished from converging rows employed in those condensers following the so-called shape ideal, I closely approximate a natural flow con-v dition and set up a tranquil and unimpeded flow of vapor from substantially allparts of the condenser toward the more effective condensing surface at the cold end. Such an arrangement of tubes also contributes to another feature of my invention, viz., that theminimum number of tubes is located at the top of the condenser with a more or less gradual increase in the number of rows as the bottom of the condenser is approached, so that the maximum condensing surface per unit of available space is obtained at the bottom of the bundle. With this arrangement of tubes, the falling condensate within the bundle imposes a minimum resistance within the vapor circuit and also a minimum resistance to the desired natural flow. This is apparent when it is considered that the maximum amount of condensate; is formed at, or adjacent to the bottom of the tube bundle and consequently, has a minimum distance through which it is forced to fall. Another advantageous feature of my invention, which will be described later and in connection with Figs. 13 and 14, is that the tube spacing employed materially reduces the number of tubes which are subjected to the detrimental efiect of corrosion and erosion caused by the liberation of air in the water circuit.

It will, of course, be apparent that acondition of natural flow maybe approximated by a tube spacing which employs other than vertical rows of tubes located in parallel relation.

Vertical rows of tubes in parallel relation are, however, preferred since they impose less obstruction to the natural vapor flow than other arrangements in that they provide unimpeded channels of substantial length in the direction of vapor flow and therefore tend to promote a more tranquil flow toward the region of highest heat head than could otherwise be obtained. It will be further apparent that by assuming the same steam velocity at the entering edge of each horizontal section and then adopting a horizontal spacing in accordance with this assumption, the channels above referred, to, in eifect extend the full length of the condensing chamber and from the top to the bottom thereof.

I realize that it is not novel to decrease the tube spacing from the top to the bottom of the condenser, but it should be .noted that the tube spacing employed by me differs from the tube spacing inv prior condensers in that it provides for close approximation to natural flow toward the entire lower edge of a rectangular tube sheet, and further provides for an increased flow per square foot of condensing surface at the cold end of the condenser. That is to say, I have departed from the modern tendency which is to employ condensers either circular or triangular in cross section and in which the flow areas decrease in such ratio as to provide only for vertical penetration. In such condensers the in-' creased steam load for the more effective portions of the condensing surface, must be mechanically forced to enter the tube bundle or special steam lanes must be provided, either through or around the tube bundle, to accommodate what has been termed a longitudinal flow of steam within the condenser chamber. In fact, I have heretofore resorted to mechanical expedients for occasioning or accommodating 1 such a longitudinal flow, but the present invention distinguishes from all'such prior condensers and prior practice in that the spacing of allthe tubes in thebundle is such as to accommodate aclose approximation of a natural flow condition. throughout all portions of the conral flow lines.

or for artificially impeding the flow, detrimentally affects the efficiency of the condenser. Any means employed for mechanically directing the line of fluid flow necessarily occasions abrupt changes in direction of flow and necessarily increases the pressure drop encountered within the condensing chamber, and distorts the natu- In addition, abrupt changes in fiow set up turbulence and eddy currents, which further increase the resistance to fiow and threfore further accentuate the detrimental condition which detracts from the efficiency of the condenser installation.

In Figs. 9 and 10 I have diagrammatically illustrated a condenser embodying features of my invention. As there shown, the shell 16 is provided with an inlet port 17, located at the top of the condensing chamber. While all but the lowermost row of tubes 26 are omitted from Figure 9, the tube spacing is as indicated in Fig.

10, and, as'is usual, thetubes extend from a tube sheet 18, at the cold end, to a tube sheet 19 at the not end of the condenser. The inlet port 20 to the inlet water box 21 is located below the confines of the tube sheet, whereas the outlet 22v of the water box 23 at the hot end of the condenser islocated above the tube sheet 19. The air offtake port 24 is located adjacent the lowermost edge of the tube sheet 18 at the cold end of the condenser and is provided with a shield 25, which extends transversely across the condenser but is located below the bundle of tubes contained therein.

Its function is to in effect provide an air offtake port which extends substantially across the cold tube sheet and adjacent the lower edge thereof and which therefore promotes a condition of natural flow. It will be apparent that all air and vapor entering the air oiftake portmust first pass through the space 25a in contact with, or in close proximity to the lower edge of the cold tube sheet. It will also be apparent that with this arrangement each of theassumed duplicated condensers heretofore referred to, receives steam in equal amounts from the common inlet, and each is provided with an air offtake port located in the region of its most effective condensing surface.

Asshown, the shield, in effect, encloses a chamber bounded on two sides by the bottom of the condenser and the lower portion of the tube sheet and the. inlet 25a to this chamber, is immediately adjacent to the tube sheet and extends across 5 the width of the condenser.

In the condenser illustrated I have shown two steam lane plates 27 one located on each side of the center line and eachextending substantially the full length of the condenser. The hot 0 well 23 is located adjacent the hot end of the condenser, and as shown in Fig. 11, steam from the lane, defined by the plates 2'7, enters the hot well'and is vented into the condensing chamber below the tube bundle, through the vents 29. The shield 25 is preferably provided with a condensate drain 30 located immediately adjacent to the bottom of the condenser, and a dam 31' is located adjacent thereto for'insuring such a level of condensate within the interior of the space conporting tubes. termediate. its ends and its ends are'rigidly sefined by the shield as will seal the drain 30. Shields 32 may be employed between the bottom row of tubes 26 and the bottom of the condenser for directing steam from the condensate space into the tube bundle. These shields are vented as at 32a for the passage of condensate.

As disclosed by the drawings, I have eliminated all bailles within the tube bundle for directing or otherwise imposing resistance to the fiow of gaseous media through the tube bundle. I employ a series of condensate collecting trays which are located above the air ofitake slot or passage 25a. As shown, these trays extend substantially the entire width of the condenser and are so arranged that they impose substantially no resistance to the flow of gaseous media toward the more effective condensing surfaces. They are so formed that they collect dropping condensate and thereby reduce the resistance to the flow of gaseous media which would otherwise be cccasioned by a heavy sheet or curtain of condensate in the zone of air and non-condensible vapor removal. Two such trays are illustrated and their sole function is to collect condensate 'I and deliver it to the space immediately adjacent the lateral walls of the condensing chamber. For

this purpose the lips 34 of the trays are notched at each end as at 340.; Where the trough plates 27 extend the full length of the condenser, as

T shown in Figs. 9 and 10, the trays are arranged on both sides of the center lane defined by these plates and the notches 34a are located as illustrated in Fig. 10. Y

The drawings disclose a relatively short tray .55 extending from the tube sheet 18 a short distance into the condensing chamber and a somewhat wider tray 36 located within the condensing chamber below the plate and spaced from the tube sheet. With this arrangement the condenser is provided with a zone extending across its entire width, which is relatively free from dropping condensate.

Where the trough plates 27 extend the full length of the condensing chamber I employ two air offtake ports, one being located in each side of the condenser shell. It will be apparent that the shield 25 may be formed in two parts to accommodate the trough construction illustrated. This arrangement of apparatus is very advantageous with a condenser having a divided water box, since one portion of the condenser may be continued in operation and operate with relatively high efiiciency' while the water circuit of the other portion is being cleaned out or repaired.

l i The tube supports are so constructed as to impose the least possible resistance to the natural flow of the gaseous media. As shown in Fig. 10, each tube support is cored or cut out between tube rows so as to provide as large openings 38 through it as are practical, the intentbeing to so form the tube supports that they provide only such mechanical strength as is necessary to support the tubes, and accommodate the natural flow to the greatest extent possible.

With the further idea of minimizing the resistance necessarily occasioned by the interpositioning of the tube supports in the vapor circuit I preferably employ what maybe termed self sup- Each tube is bowed upwardly. in

cured to the respective tube sheets. Under such conditions .each tube, in effect, constitutes an arch, but because of its length and flexibility, is

not wholly self sustaining and 'a form of tube support must therefore be employed with it- The tube supports may, however, be made so light that they are, in efiect, merely spacers and their function is hardly more than to hold the intermediate portions of each tube in the proper positions with relation to the other tubes, and to some extent control the bowing of the'tubes under variations of temperature. It will be apparent that where tubes are employed which have a greater coefiicient of expansion than the condenser shell, an increase in temperature will elongate the tubes and consequently where both ends are fixed to the tube sheet, increase the initial bow. It will also be apparent t1 in order to insure upward bowing of the tubes under all conditions it is necessary to employ supportsor spacers which move with the tubes as they expand and contract. For this reason the tube supportscontemplated by this invention are capable of moving in a vertical plane in response to the expansion and contraction of the tubes.

As shown in 16*, the tube support lil is held in place by pins ll suitably carried by the condenser shell. T'nese pins extend through slots 42 formed in the tube supports and the slots are elongated vertically so as to permit vertical move- Z00 ment of the supports. It will therefore be apparent that the supports act as guides and spacers for the bowed tubes and that the slot and pin connections, by guiding the supports in their vertical movement, in effect, control the bowing and the relative positions of the tubes under all variations of temperature conditions. Where bowed tubes are employed the vertical spacing, between the tubes, immediatelybelow the trays 35 and 36 and those trays, is such as to permit the free bowing of those tubes. I

In Figs. 11 and 12 I have diagrammatically shown a modified form of tube support which may be conveniently employed in connection with my invention. 1

As shown, the ordinary tube support is replaced by what may be termed a sectional support made up in sections which extend from the top to'the bottom of the condenser and wh chare prefer-- ably staggered with relation to each other so as to impose the least possible resistance to the natural flow of gaseous media. Each section 43 is, in eiiect, a strip and is so punched as to receive a vertical group of tubes. As shown in Fig. 12

each such strip is suspended by a slot and pin space as possible between them and, like the i supports heretofore described move with the tubes during their expansion and contraction and guide the bowing of the tubes. This arrangement 7 of tube support or guide is advantageous from the manufacturing standpoint, since the strips are all of substantially the same shape and the tube pattern is such as to permit the stamping or shearing of a number of strips at the same time.

Another feature of my invention is illustrated in Figs. 13 and 14 of the drawings. condensers employing a siphon seal system, a barometric leg is employed in connection with the discharge water box at the hot well end of the condenser; With this arrangement the pressure of the water within the cooling system de- L? In all the 1] creases toward the top of that system with the result that a vacuum is actually encountered which increases toward the top of the system. Air entrained by the cooling water and air in solution in that water is liberated under the effect of this vacuum and is a source of trouble because it causes corrosion and therefore promotes erosion of such tubes as are exposed'to it. It will be apparent that where air is thus liberated in the inlet water box, an air pocket may form in the upper portion of the inlet water box and, in any event, some of the upper tubes of the bundle are at times partially filled with air and consequently are subjected to rapid corrosion and erosion. The tube spacing heretofore described minimizes the effect of this condition, since relatively few tubes are located at the upper portion of the bundle and consequently a minimum number of tubes are exposed to air so liberated. In order to completely overcome the difficulty, I contemplate employing corrosion resisting tubes at the top of the condenser which are so located that they will readily pass air from the top of the inlet water box to the outlet water box. I contemplate forming these tubes from a ferrous alloy capable of resisting corrosion, and preferably having the same, or substantially the same ooeflicient of expansion as the condenser shell. As shown, a series of tubes 50 is provided immediately adjacent the steam inlet port of the condenser, so that they communicatewith the upper portion of the water box.

It will be noted that the water box 21a is extended considerably above the uppermost tubes 26a of the main bundle, and that the tubes 50 communicate with the uppermost part of the water box and are therefore spaced at considerable distance above the main tubes of the bundle. There are two reasons for this; first, the water box 'is extended above the main bundle of tubes to prevent air from entering those tubes; and second, it is necessary to space the fixed tubes 50 sufliciently above the main tubes so that they will not interfere with the bowing of those tubes and the resultant movement of the tube spacers employed.

It will be apparent that it is desirable to maintain these tubes 50 as nearly horizontal throughout their entire length as possible so that they will provide a free air vent from the inlet water box to the outlet water box. For this reason, I provide separate and fixed tube supports 51 for the tubes 50 to prevent their sagging intermediate their ends. The tubes 50 preferably have at least the same spacing as the tubes at the entrance edge of the main bundle, but a wider spacing may be employed, if desired.

In condensers employing tubes secured to the tube sheet by means of packings and ferrules so as to permit longitudinal movement of the tubes with relation to the shell, the tubes 50 may be included in the top row of tubes of the main bundle, in which case the water box need not be extended upwardly as illustrated in Fig; 13. I, however, prefer the arrangement illustrated, since it insures a complete flooding of all the main tubes of the bundle thereby increasing their efficiency and also reduces the possibility of erosion and corrosion heretofore referred to. It will, however, be apparent that with the tube spacing herein disclosed, it would be permissible to employ tubes formed from a ferrous alloy as the first few rows of tubes of the main bundle where non-ferrous tubes of the main bundle are not rigidly secured to both tube sheets, and that such an arrangement would insure complete flooding of the non-ferrous tubes without necessitating an extension of the water boxes. 1

While I have described what I now consider to be the preferred embodiment of my invention, it will be apparent to those skilled in the art that various changes, additions, omissions and modifications of the apparatus illustrated, may be resorted to without departing from the spirit and. scope of my invention.

What I claim as new and desire to secure by Letters Patent is:

1. A high capacity surface condenser comprising a shellenclosing a condensing chamber and having an inlet port, a condensate outlet and an air offtake port, water circulating means associated with said shell, tubes traversing said cham ber and increasing in number in the direction of steam penetration, and at least one support for such tubes, such tubes and said support being so arranged as to permit a substantially natural flow of vapor throughout substantially all parts of the condensing chamber.

2. A surface condenser comprising a shell enclosing a condensing chamber and having an inlet port adjacent the top thereof and an air offtake port adjacent the bottom thereof, and a condensate outlet, water circulating means associated with said shell, and tubes traversing said chamber and communicating with said means, said tubes increasing in number in the direction of steam penetration and being so spaced and distributed within said chamber as to provide for a substantially natural flow substantially throughout the vapor circuit of said condenser.

3. A surface condenser comprising a shell enclosing a condensing chamber and having an inlet port adjacent the top thereof and an air offtake port adjacent the bottom thereof, and a condensate outlet, water circulating means associated with said shell, and tubes traversing said chamber and communicating with said means, said tubes increasing in number in the direction of steam penetration and being arranged in substantially parallel rows and so spaced as to provide'for a substantially natural flow substantially throughout the vapor circuit of the condenser.

4. A surface condenser comprising a shell enclosing a condensing chamber and having an inlet port in the. top thereof, and an air offtake port adjacent the bottom of said chamber and a condensate outlet, water circulating means communicating with said shell, tubes traversing said chamber and communicating with said means, said tubes being arranged in substantially parallel vertical rov/s increasing in number of rows from the top toward the bottom of said chamber and so spaced as to provide for a substantially natural flow throughout the vapor circuit of the condenser.

5. A surface condenser comprising a shell enclosing a condensing chamber and having an inlet port in'the top thereof, and an air offtake port adjacent the bottomof said chamber and a condensate outlet, water circulating means communicating with said shell, tubes traversing said chamber and communicating with said means, said tubes being arranged in substantially parallel vertical rows increasing in number of rows from the top toward the bottom of said chamber and so spaced horizontally as to provide for a substantially natural flow of vapor within the vapor circuit of the condenser.

6. A surface condenser comprising a shell enclosing a condensing chamber and having an inlet port in the top thereof, and an air ofitake port adjacent the bottom of said chamber and a condensate outlet, water circulating means communicating with said shell, tubes traversing said chamber and communicating with said means, said tubes being arranged in substantially parallel vertical rows increasing in number of rows from the top toward the bottom of said chamber and so spaced as to provide for a substantially natural flow of thegaseous media throughout said chamber, a tube support for said tubes, having vapor delivery openings formed therein substantially throughout its entire extent.

7. A surface condenserv comprising a shell enclosing a condensing chamber and having an inlet port in the top thereof, and an air ofitake port adjacent the bottom of said chamber and a condensate outlet, water circulating means communicating with said shell, tubes traversing said chamber and communicating with said means, said tubes being arranged in substantially parallel vertical rows increasing in number of rows from the top toward the bottom of said chamber and at least one tube support extending transversely of said chamber and having vapor delivery apertures formed therein between vertical rows of tubes, said tube rows being so spaced horizontally and said apertures in said support,

being such as to provide for a substantially natural flow throughout the vapor circuit of the condenser. e

8. A surface condenser comprising a shell enclosing a condensing chamber, and having an inlet port in the top thereof, and an air offtake port adjacent the bottom of said chamber, a condensate outlet, water circulating means associated with said shell and including an inlet water box, tubes extending longitudinally of said chamber and communicating with said water circulating means, at least one tube support for said tubes extending transversely of said chamber and having vapor delivery openings formed therein, said tubes being so spaced and said openings being so arranged as to provide for a substantially natural flow of gaseous media throughout the vapor circuit of said condenser.

9. A surface condenser comprising a shell enclosing a condensing chamber, and having an inlet port in the top thereof, and an air offtake port adjacent the bottom of said chamber, a condensate outlet, water circulating means associated with said shell and including an inlet water box, tubes extending longitudinally of said chamber and communicating with said water circulating means, at least one sectional tube support extending across said chamber, said tubes being so spaced and the sections of said support being so spaced as to permit of a substantially natural flow of the gaseous media throughout the vapor circuit of the condenser.

10. A surface condenser comprising a shell enclosing a condensing chamber, and having an inlet port in the top thereof, and an air oiftake port adjacent the bottom of said chamber, a condensate outlet, water circulating means associated with said shell and including an inlet water box, tubes extending longitudinally of said chamber and communicating with said water circulating means, at least one sectional tube support for said tubes extending across said chamber with the sections thereof spaced one from the other and having vapor delivery apertures formed therein, said tubes being so spaced and said sectional support being so arranged as to permit a substantially natural flow of the vapor throughout the vapor, circuit of said condenser.

11. A surface condenser comprising a substantially rectangular shell enclosing a substantially rectangular condensing chamber and having a steam inlet port, located at the top thereof, an air ofiftake port located at the bottom and adjacent one end thereof, and a condensate outlet, water circulating means associated with said shell and including an inlet water box located'at one end'of said chamber, tubes extending longitudinally of said chamber and communicating with said water circulating means, a tube support extending across said chamber and having vapor delivery openings formed therein and throughout substantially its entire extent, said tubes being so spaced, said openings being so arranged and said air ofltake port being so located as to promote a substantially natural flow within the vapor circuit of the condenser.

12. A surface condenser comprising a substan tially rectangular shell enclosing a substantially rectangular condensing chamber and having a steam inlet port, located at the top thereof, an air oiftake port locatedat the bottom and adjacent one end thereof, and a condensate outlet, water circulating means associated with said shell and including an inlet Water box located at one end of said chamber, tubes traversing said chamber, communicating with said means and arranged in substantially parallel vertical rows with the number of rows increasing toward the bottom of said chamber,and at least one tube sup-. port extending across said chamber and having vapor delivery openings formed therein between vertical rows of tubes, said tubes being so spaced, said openings so arranged and said olftake port so located as to promote a substantially natural flow of the gaseous media throughout the vapor circuit of said condenser.

13. A surface condenser comprising a substantially rectangular shell, enclosing a substantially rectangular condensing chamber, and having an inlet port at the top thereof, air oiitake adjacent the bottom thereof, and a con ensate outlet, tubestraversing said chamber, an inlet water box associated with said shell and communicating with one end of said tubes, an outlet water box associated with said shell and communicating with the other end of said tubes, tube supports located within said chamber, each having vapor delivery openings formed therein and means associated with said oiitake providing an air offtake passage extending substantially across said condensing chamber near the bottom thereof and adjacent said inlet water box, said tubes being so spaced and said vapor delivery openings being so arranged as to permit a substantially natural flow substantially throughout the vapor circuit of said condenser.

14. A surface condenser comprising a substantially rectangular shell, enclosing a substantially rectangular condensing chamber, and having an inlet port at the top thereof, an air oiftake adjacent the bottom thereof, and a condensate outlet, tubes traversing said chamber, water circulating means associated with said shell and com- ,municating with said tubes, a tube support within said chamber, means within said chamber associated with said air ofltake providing an air ofitake passage communicating with and extendnatural flow of gaseous media throughout substantially the entire vapor circuit of said condenser.

15. A condenser comprising a substantially rectangular shell enclosing a substantially rectangular condensing chamber and having an inlet port in the top thereof, an air offtake port and a condensate discharge, a water circulating system associated with said shell and including an inlet Water box located at one end thereof, tubes traversing said chamber and communicating with said system, and means associated with said air offtake providing an air ofitake'passage extending substantially across said chamber near the bottom thereof and adjacent said inlet water box, said tubes being so spacedand distributed within said chamber as to permit a substantially natural flow of gaseous media substantially throughout the vapor circuit of the condenser.

. 16. A condenser, comprising a substantially rectangular shell enclosing a substantially rectangular condensing chamber and having an inlet port in the top thereof, an air offtake port and a condensate discharge, a water circulating system associated with said shell and including an inlet water box located at one end thereof, tubes traversing said chamber and connnunicating with said system and increasing in number in the direction of steam penetration, a tube support extending across said chamber and provided with vapor delivery openings therein, said tubes being so spaced and said openings being so arranged and said air ofitake being so located as to promote a substantially natural flow of gaseous media substantially throughout the vapor circuit of the condenser.

17. A condenser comprising a shell enclosing a condensing chamber and having a steam inlet port in the top thereof, a condensate outlet and an air ofltake, a Water circulating system associated with said shell, tubes traversing said chamber and included in said system and arranged in substantially vertical rows located in substantially parallel relation, with the number of rows increasing in the direction of steam penetration, and a tube support extending across said chamber and having vapor delivery openings located between adjacent parallel tube rows substantially throughout the extent of said support, said vertical rows of tubes being so spaced and said openings being so arranged in said support and the efiective communication between said air offtake and said chamber being so located as to promote a substantially natural flow substantially throughout the vapor circuit of the condenser.

18. A condenser comprising a shell enclosing a condensing chamber, and having a steam inlet port, a condensate outlet, and an air ofitake, a water circulating system associated with said shell, tubes traversing said chamber, included in said system and increasing in number in the direction of steam penetration, a tube support for said tubes located within said chamber and having vapor delivery openings formed therein throughout substantially its entire extent, said tubes being so spaced,'said openings being so arranged and the effective communication between said air ofitake and said chamber being so located within the chamber as to promote a substantially natural flow substantially throughout the vapor circuit of the condenser.

19. A condenser comprising a shell enclosing a condensing chamber and having a steam inlet' shell, tubes traversing said chamber, included in saidcirculating system and arranged in parallel rows with the number of rows increasing in the direction of steam penetration, the spacing between such parallel rows being such as to permit a substantially natural flow of vapor substantially throughout said chamber.

20. A condenser comprising a shell enclosing a condensing chamber and having a steam inlet port, a condensate outlet and an air oiitake, a 35 water circulating system associated with said shell, tubes traversing said chamber, included in said system and arranged in parallel rows with the number of rows increasing in the direction of steam penetration, and a tube support for said 290 tubes having vapor delivery orifices formed therein between such parallel rows of tubes, the spacing of such parallel rows and the arrangement of said vapor delivery openings being such as to permit a substantially natural flow substantially '95 throughout the vapor circuit.

21. A condenser comprising a shell enclosing a condensing chamber, and having a steam inlet port, a condensate outlet and an air offtake, a water circulating system associated with said 170 shell, a bundle of tubes traversing said shell, including in said system and having the tubes thereof arranged in sections in the direction of steam penetration, with the tubes of each'such section arranged in substantially parallel rows, '05 such rows of each section being so spaced that the free space between such rows and at the entering edge of each such section bears substantially the same relation to the quantity of steam entering such section as the free space 0 at the entering edge of the tube bundle bears to the quantity of steam entering the bundle, the efiective communication between said air offtake and said chamber being located adjacent the exit edge of the section having the 1,}; greatest number of parallel rows of tubes.

22. A condenser comprising a shell enclosing a condensing chamber and having a steam inlet port, a condensate outlet, and an air ofitake, a water circulating system associated with said shell and including a water inlet box,a bundle of tubes traversing said shell and included in said Water circulating system, and having the tubes thereof arranged in sections in the direction of steam penetration of the bundle, with the tubes ofreach such section arranged in substantially parallel rows so spaced that the free space between such rows at the entering edge of each such section bears substantially the same relation to the quantity of steam entering such section as the free space at the entering edge of the bundle bears to the quantity of steam entering the bundle, and a tube support having vapor delivery openings formed therein and between parallel rows of tubes of such sections, the ef- 13 fective communication between said air ofitake and said chamber being located adjacent the exit edge of such section most remote from the entering edge of the bundle and adjacent said inlet water box.

23. In combination in a condenser, a shell enclosing a condensing chamber and having a steam inlet port, a condensate outlet and an air offtake port formed therein, a water circulating system associated with said shell and including an inlet water box at one end of the shell and an outlet Water box located at the other end of the shell, a bundle of tubes located within said chamber, included in said system between said water boxes, said bundle being divided into sections in 'tubes located within said chamber,

the direction of steam penetration with the tubes of each such section arranged in substantially:

parallel rows extending substantially in the direction of steam penetration, and with the free space between such parallel rows at the entering.

edge of each such section bearing the same relation tothe quantity of steam entering the sec tionas the free space at the entering edge of the bundle bears to the quantity of steam entering thebundle, and a support for the intermediate portions 'of said tubes having vapor delivery openings formed between parallel rows of each section, said air offtake having effective coinmunication with said chamber adjacent said inlet water box and near the exit edge'of the tube bundle, and said condense e outlet being located near said outlet water box.

24. In combination in a condenser, a shell enclosing a substantiallyrectangular condensing chamber, and having a steam inlet port in the I top thereof, a condensate outlet, and an air offtake port, a water circulating system associated with said shell and including an inlet water box,

thesefiective communication between said chamber and said air offtake extending substantially across said chamber near .the bottom thereof and adjacent said water box, a bundle of tubes located within said chamber, included within said system and communicating with said water box, said bundle being divided into sections with the tubes of each section arranged insubstan- .tially vertical, horizontally spaced, parallel rows and with the free space between said vertical rows at the entering edgeof each section bearing substantially the same relation to the quantity of steam entering such section as the-free space at the entering edge of the bundle bears to the quantity ofv steam entering the bundle, a tube support located located within said chamber intermediate the ends of said tubes andhaving vapor delivery openings formed therein between the parallel rows of tubes of each section whereby substantially unimpeded paths are provided extending throughout the length of said chamber and toward the effective communication between said chamber and said air offtake port.

25. In combination in a condenser, a shell enclosing a substantially rectangular condensing chamber and having a steam) inlet port formed in the top thereof, a condensate outlet, and an air ofitake, a water circulating system associated with said shell and including an inlet water box, the effective communication between said air offtake and said shell extending substantially across the chamber and being located near the bottom thereof and adjacent said water box, a bundle of included within said system and communicating with said water box, the tubes of said bundle being arranged in substantially parallel, horizontally spaced, vertical rows increasing in number from the top to the bottom of said'condenser and being arranged in substantially duplicate groups transversely of said chamber, and a tube support located within said chamber and extending transversely thereacross and provided with vapor delivery openings between the vertical rows of tubes,

said tubes being so spaced and said openings being so formed as to provide substantially. un-

impeded paths extending throughout the length of said chamber and toward said eifective communication between said chamber and said air oiftake.

26. In combination in a condenser, a shell enclosing a substantially rectangular condensing chamber, and having a steam inlet port, an air offtake and a condensate outlet, a circulating water system associated with said. shell and including a divided inlet water box and a divided outlet water box, a bundle of tubes located within said chamber and included within said system, the tubes of said bundle being so spaced as to permit a substantially natural flow of vapors toward the inlet water box end of the condenser, partitionsextending from the bottom of said shell upwardly into said bundle and constituting a steam trough extending substantially throughout the length of the shell and communicating at one end with the condensate outlet, said trough also dividing the lower portion of said bundle into two substantially equal groups of tubes, and an'efiective communication between said chamber and said air oiftake located on each side of said trough and adjacent the exit edge of the bundle.

27. In combination in a condenser, a shell enclosing a condensing chamber and having an inlet port in the top thereof, tube sheets secured to said shell and located at the ends of said chamber, tubes traversing said chamber and arranged in parallel, rows each such tube being securedzat each end to oneof said sheets and bowed intermediate its ends, a water box cooperating with each such tube sheet, movable tube supporting means intermediate the ends of said chamber engaging said tubes and providing vapor delivery passages between each row of tubes and means for guiding the movement of said tube supporting means in response to expansion and contraction of said tubes 1 28. In combination in a condenser, a shell enclosing a condensing chamber and'havin'g an inlet port in the top thereof, tube sheets secured to said shell and located at. the ends of said chamber, tubes arranged in substantially vertical rows traversing said chamber, each such tube being rigidly secured at each end to one of said tube sheets and bowed intermediate its ends, a tube spacer located within said chamber intermediate the ends thereof for spacing such tubes and having vapor delivery openings formed therein throughout the entire extent thereof and located between the vertical rows of tubes and means for guiding themovement of said spacer in response to expansion and contraction of said tubes.

29. In combination with a condenser, a shell enclosing a condensing chamber, tube'sheets secured to the shell and located at the ends of said chamber, tubes traversing said chamber and arranged in substantially parallel rows each such tube being rigidly secured at each end to one of said tube sheets and bowed intermediate its ends, and at least one tube spacer located Within said "chamber intermediate said tube sheets and cut away between said rows of tubes engaged thereby to minimize the weight thereof and provide vapor delivery openings therethrough and means for guiding the movement of said spacer in response to the expansion and contraction of said tubes.

, 30. In combination in a condenser, a shell enclosing a condensing chamber and having an inlet port formed therein at the top thereof and a condenser outlet port and an air oiftake port adjacent the bottom thereof, but spaced one from the other, a water circulating system associated with said shell and including an inlet water box at one end of said shell, an outlet water box at the other end of said shell and a bundle of tubes located within said chamber and communicating with bothsaid water boxes, said tubes being artration with the tubes of each such section arranged in substantially parallel rows increasing in number in the direction of steam penetration and with the free space between such rows at the entering edge oi-each such section-bearing substantially the same relation tothe quantity of steam entering'the section as the free space at the entering edge of the bundle bears to the quantity of steam entering the bundle, condensate trays located at one end of said chamber adjacent the inlet water box and extending transversely across said chamber above said air ofitake port, said air offtake port having effective communication with said-chamber adjacent said inlet water box and near the exit edge of said tube bundle and substantially across said chamber.

' 31. In combination with a condenser, a shell enclosing a condensing chamber and havinga steam inlet port formed adjacent the top thereof, a condensate outlet port and an air oiitake port formed therein adjacent the bottom thereof, a water circulating system associated with said shell and including an inlet water box at one end and an outlet water box at the other end of said chamber and a bundle of tubes located within said chamber, said bundle of tubes'being divided into sections in the direction of steam penetration with the tubes of each section arranged in substantially vertical rows increasing in number in the direction of steam penetration, and with the free space between such vertical rows at the entering edge of each such section bearing substantially the same relation to the quantity of steam entering the section as theiree space at the entering edge of the bundle bears to the quantity of .steam entering the bundle, said air offtake port being located adjacent said inlet water box :and extending transversely across said chamber and below said tubes, condensate trays located withinsaid bundle above said air offtake port and extending substantially across said bundle.

32. In combination with a condenser, a shell enclosing a condensing chamber and having a "steam inlet port formed adjacent the top thereof, a condensate outlet port. and an air ofitake port formed therein adjacent the bottom thereof, a water circulating system associated with said shell and including an inlet water box at one end and an outlet water box at the other end of said shell and a bundle of tubes located within said chamber, said bundle of tubes being divided into sections in the direction of steam'penetration with the tubes of each section arranged in substantially vertical rows increasing in number in the direction of steam penetration, and with the free space between such vertical rows at the entering edge of each such section bearing substantially the same relation to the quantity of steam entering the section as the free space at the entering edge of the bundle bears to the -quantity of steam entering the bundle, said air ofitake port being located adjacent said inlet Water box and extending substantially across said chamber below said tubes, condensate. trays located within the bundle of tubes above said air ofitake port and extending substantially across said bundle and at least one tube spacer located within said chamber intermediate the ends thereof and providing vapor delivery openings between the vertical rows of tubes in each such section whereby substantially unimpeded paths are proa between said chamber and said air offtake port.

33. In combination in a condenser, a ferrous shell enclosing a condensing chamber and having a steam inlet port formed in the top thereof, a water circulating system associated with said shell, comprising a water box located at each end of said shell, a group of non-ferrous tubes travers ing said chamber and included in said system, a plurality of non-corrosive ferrous tubes included in said system and spaced above said first mentioned tubes, said water boxes both extending. above the uppermost row of non-ferrous tubes to provide an air space therein extending substantially across the shell of the condenser.

34. In combination in a condenser, a shell enclosing a condensing chamber, tube sheets secured to said shell and located at the ends of said chamber, a group of non-ferrous tubes traversing said chamber and secured to said tube sheets, a separate water box located at each end of said chamber, associated with the adjacent tube sheet and extending above the upper row of said tubes to provide an air space extending substantially across said shell, and a group of tubes intervening between said inlet 'port and said first mentioned group of tubes and communicating with the upper portions of said water boxes.

35. In combination in a condenser, a shell enclosing a condensing chamber and having an inlet port in the top thereof, tube sheets secured to said shell and located at the ends of said chamber, tubes traversing said chamber, each being rigidly. secured at each end to one of said tube sheets and bowed intermediate its ends, a separate water box associated with each tube sheet and extending above the upper row of said tubes so as -to provide an air space within the water box extending substantially across said shell and a plurality of tubes having the same coefficient of expansion as said shell spaced from said first mentioned tubes, secured to said tube sheets and communicating with the upper portion of each such water box.

36. In combination in a condenser, a shell enclosing a condensing chamber and having an inlet port formed in the top thereof, tube sheets secured'to said shell and located at the ends of said chamber, tubes traversing said chamber, each being rigidly secured at each end to one of said tube sheets and bowed intermediate its ends, a water box associated with each tube sheet and extending r above the upper row of said tubes to provide an air space therein extending substantially across said shell and a row of non-corrosive ferrous tubes traversing said chamber but located above said first mentioned tubes and secured to said tube 2 sheets and communicating with such air space, said last mentioned tubes being straight and having substantially the same coefiicient of expansion as said shell.

37. A surface condenser comprising a shell en- 1' 3 inlet water box, an outlet water box and tubes traversing said chamber and communicating with said water boxes, said tubes being arranged in substantialliy parallel rows increasing in number or rows in the direction of steam penetration, and

tube supporting means located within said chamber intermediate the ends thereof, said tubes be ing so spaced and said tube supporting means being so formed as to provide for a substantially natural flow of gaseous media throughout said chamber.

. closing a condensing chamber and having an inlet port, an air offtake port and a condensate outlet port formed therein, a water circulating system associated with said shell and including an inlet water box, an outlet water box and a bundle of tubes located within said chamber and communicating with said waterboxes, said air offtake port being located within said chamber adjacent said inlet water box and the exit edge of 'said' bundle and extending substantially across said chamber, tube supporting means located within said chamber intermediate the ends thereof, and condensate trays located within said chamber and within said bundle and adjacent said inlet water box and extending substantially across said chamber, said tubes being arranged in parallel rows increasing in number in the direction of steam penetration, and said tubes being so spaced, said tube supporting means so formed and said trays so located as to contribute to a substantially natural flow of gaseous media throughout said chamber.

39. In combination in a condenser, a shell having a steam delivery port, an air offtake port and a condensate delivery port formed therein, tube sheets secured to said shell and located at opposite ends of said chamber, a bundle of tubes traversing said chamber, each such tube having each end rigidly secured to one of said tube sheets and being bowed intermediate its ends, the tubes of said bundle being arranged in sections in the direction of steam penetration, movable tube spacing means intermediate the ends of said chamber and engaging tubes of said bundle and having apertures formed therein in balanced relation with all the tubes and over the entire extent of said bundle, and means for guiding the movements of said spacer in response to the expansion and contraction of said tubes.

40. A high capacity surface condenser comprising a shell enclosing a condensing chamber and having an inlet port, a condensate outlet port and an air olftake port formed therein, an inlet water box at one end and an outlet water box at the other end of said shell, tubes traversing said chamber, communicating with said water.

boxes and arranged in parallel rows increasing in number in the direction of steam penetration, said air offtake port being located at the opposite side of said condenser from said inlet port and adjacent to said inlet water box, and at least one support for such tubes located within said chamher, said tubes and said support being so arranged to permit a substantially natural flow of vapor throughout all parts of said chamber.

41. A high capacity surface condenser comprising a shell enclosing a condensing chamber and having an inlet port, a condensate outlet port and an air offtake port formed therein, a water circulating system associated with said shell and including a water box at each end of said chamber and tubes traversing said chamber, and communicating with said water box, said air offtake port being located adjacent to the inlet water box and said tubes being arranged in parallel rows increasing in number in the direction of steam penetration, at least one support for said tubes located within said chamber intermediate the ends thereof and such tubes and said support being so arran ed as to permit a substantially natural flow of vapor throughout substantially all parts of the condenser.

, 42. A surface condenser comprising a shell enclosing a condensing chamber and having an inlet port in the top thereof, an air offtake port adjacent the bottom and at one end thereof and a condensate outlet port adjacent the bottom thereof, a water circulating system associated with said shell and including a bundle of tubes traversing said chamber, said tubes being ar,-

, ranged in substantially vertical rows increasing in number from the top toward the bottom of said chaniberand so spaced as to provide a substantially natural flow throughout the vapor circuit cf the condenser, condensate trays located at one end of said chamber within said bundle of tubes and so located as to shield said air oiitake, but to produce a minimum effect on the natural flow of the vapors within said chamber.

43. A surface condenser comprising a shell enclosing a condensing chamber and having an said chamber intermediate the ends thereof, said tubes being arranged in substantially vertical rows increasing in number from the top toward the bottom of said chamber, and said tubes being so spaced and said tube supporting means so formed as to provide for a substantially natural flow throughout the vapor circuit of the condenser, condensate trays located at the inlet -water box end of said chamber and within said tubes so as to shield said air offtake port but so arranged as to produce a minimum effect on? the natural flow of vapors within said chamber.

44. In combination in a condenser, a shell enclosing a condensing chamber and having an inlet port formed therein at the top thereof, and a condensate outlet port and an air ofltake port formed therein adjacent the bottom thereof but spaced one from the other, a water circulating system associated with said shell, and including an inlet water box at one end of said shell, an outlet water box at the other end of said' -l' shell, and a bundle of tubes located within said chamber and communicating with both water boxes, such tubes being arranged in sections of increased numbers of vertical rows from the top to the bottom of said chamber, with the rows of each section so spaced that the free space between such rows at the entering edge of each section bears substantially the same relation to the quantity of steam entering such section as the free space at the entering edge of the bundle bears to the quantity of steam entering the bundie, the effective communication between said air oiitake port and said chamber being adjacent the exit edge of the lowermost section, a hot well es hill,

communicating with said condensate outlet port,"

and lane plates located adjacent the bottom of said chamber extending longitudinally thereof and defining a steam lane within the lowermost section in open communication with said hot well.

and the bottom thereof, a water circulating sys- 45. In combination in a condenser, a shell entem associated with said shell and including an inlet water box at the air offtake port end of said shell, an outlet water box at the condensate outlet port end of said shell, and a bundle of tubes located within said chamber and communicating with both said boxes and arranged in sections of increased number of vertical rows of such tubes from the top to the bottom of said chamber with the rows of each section so spaced that the free space between such rows at the entering edge of each such section bears substantially the same relation to the quantity of steam entering such section as the free space at the entering edge of the bundle bears to the quantity 

